Re: [PATCH v5 00/39] i.MX Media Driver

[Steve Longerbeam]

On 03/19/2017 11:51 AM, Russell King - ARM Linux wrote:
> On Sun, Mar 19, 2017 at 11:37:15AM -0700, Steve Longerbeam wrote:
> > On 03/19/2017 05:14 AM, Russell King - ARM Linux wrote:
> > > Right now, CSI doesn't do that - it only looks at the width, height,
> > > code, and field.
> > Correct, there is currently no propagation of the colorimetry
> > parameters (colorspace, ycbcr_enc, quantization, and xfer_func).
> > For the most part, those are just ignored ATM. Philipp Zabel did
> > do some work earlier to start propagating those, but that's still
> > TODO.
>
> > > I think we've got other bugs though that haven't been picked up by any
> > > review - csi_try_fmt() adjusts the format using the _current_
> > > configuration of the sink pad, even when using V4L2_SUBDEV_FORMAT_TRY.
> > > This seems wrong according to the docs: the purpose of the try
> > > mechanism is to be able to setup the _entire_ pipeline using the TRY
> > > mechanism to work out whether the configuration works, before then
> > > setting for real.  If we're validating the TRY formats against the
> > > live configuration, then we're not doing that.
> > I don't believe that is correct. csi_try_fmt() for the source pads calls
> > __csi_get_fmt(priv, cfg, CSI_SINK_PAD, sdformat->which) to get
> > the sink format, and for the TRY trial-run from csi_set_fmt(),
> > sdformat->which will be set to TRY, so the returned sink format
> > is the TRY format.
> Look at csi_try_fmt() - it validates the source pad against
> priv->crop, which is the actively live cropping rectangle, not the
> one which has been configured for the TRY trial-run.

Ah yes, crop, I missed that. Yes you are right, looks like we
need to add a __csi_get_crop().

> Also, as I mention elsewhere, I believe the way we're doing scaling
> is completely wrong...

You might be right there too. Initially, I had no support for the 
down-scaling
in the CSI. That was added later by Philipp, I will respond with more 
there...

Steve